Thanks again. I've been a Mouseplanet member for awhile now. When I posted this question there I didn't get any useful advice (only one person who missed the point of my question and tried to develop a cost/benefit analysis showing that concierge isn't worth it). My wife and I are big Disney fans (more than could ever be properly conveyed on a message board like this), but this will be our first stay at the GF. After a week there we've got a week at the Animal Kingdom Lodge concierge, another first for us. It's tough giving up that many frequent traveler points (like we'd earn at the Swan or Marriott Orlando World Center), but I'm getting such a good deal at the Disney properties that I simply couldn't pass them up.
Thanks again for the help!